This invention relates to an ampule feeder for feeding according to prescriptions ampules and vials containing injection medication and housed randomly in a container.
Unexamined Japanese patent publications 7-300237, 8-230826 and 8-225140 disclose ampule feeders for feeding ampules housed randomly in a container.
The ampule feeder disclosed in the first publication has a head disposed under the container bottom and having a recessed top formed with a groove. The head is pushed up by a cylinder head to lift an ampule on the top of the head. The ampule thus lifted is sucked by a sucker and moved onto a conveyor.
The ampule feeder of the second publication has an ampule container with two cells partitioned by a movable partitioning plate so that the volumes of the cells are variable. A pusher rod with an ampule-receiving head is provided in each cell. The head has an inclined top surface. When each rod is pushed up to a predetermined height with an ampule on the inclined top surface of the head, the top inclined surface of the head aligns with a conveyor line, so that the ampule slides down into the conveyor line.
The ampule feeder of the third publication has an ampule feeder with an inclined bottom. A pusher having a inclined top is vertically movably inserted through a hole formed in the bottom of the container. When the pusher is pushed up to a predetermined height with an ampule on the inclined top, the inclined top aligns with an inclined platform, so that the ampule slides down onto the platform. The ampule on the platform is now pushed up by another pusher and discharged. Ampules can thus be discharged one by one without the possibility of being broken.
Ampule feeders of this type have an advantage in that there is no need to arrange ampules in containers in an orderly manner. Thus, many of today's ampule feeders are of this type.
But this type of ampule feeders have their own problems. One problem is that the pusher means is frequently pushed up with no ampule on the head. This happens because ampules put in the container in an disorderly manner tend to get stuck and deadlocked especially near the pusher.
This problem is solvable if a plurality of ampules arranged in an orderly manner are raised by a pickup means and discharged one by one. Such a pickup means has to have a length at least 1.5 times the length of ampules and a width suitable to raise a plurality of ampules in an orderly aligned state, i.e. a width substantially equal to the ampule diameter.
In this arrangement, while the ampule container having a horizontal bottom is filled with ampules, ampules will move little by little toward the pickup means. But as the number of ampules in the container decreases and the height of the heap of ampules lowers, the ampules cannot move toward the pickup means. In order to move ampules toward the pickup means even in this state, the container has to have an inclined bottom.
But such an inclined bottom reduces the volume of the ampule container. That is, an ampule container with an inclined bottom cannot store as many ampules as an ampule container with a horizontal bottom.
An object of this invention is to provide an ampule feeder which is simple in structure and which can discharge ampules one by one with high efficiency without the possibility of clogging.